Assertion : $NF_3$ is a weaker ligand than $N(CH_3)_3$.
Reason : $NF_3$ ionizes to give $F^{-}$ ions in aqueous solution.

Which of the following ligands does not show synergic bonding with a central metal atom?

For the complex $ML_2$,the stepwise formation constants for the reactions:
$M + L \rightleftharpoons ML$
$ML + L \rightleftharpoons ML_2$
are $4$ and $3$ respectively. Hence,the overall stability constant for the reaction:
$M + 2L \rightleftharpoons ML_2$
is:

Which of the following orders is correct in the spectrochemical series of ligands?

Given below are two statements: one is labelled as "Assertion $A$" and the other is labelled as "Reason $R$".
Assertion $A$: In the complexes $Ni(CO)_4$ and $Fe(CO)_5$,the metals have zero oxidation state.
Reason $R$: Low oxidation states are found when a complex has ligands capable of $\pi$-donor character in addition to the $\sigma$-bonding.
In the light of the above statements,choose the most appropriate answer from the options given below.

Give the correct order of electrical conductivity of aqueous solution of the following complexes:
$A$. $[Pt(NH_3)_6]Cl_4$
$B$. $[Cr(NH_3)_6]Cl_3$
$C$. $[Co(NH_3)_4Cl_2]Cl$
$D$. $K_2[PtCl_6]$